Taxol is a natural product with anti-cancer activity. Because natural sources of taxol are limited, synthetic methods for producing taxol have been developed, e.g., K. C. Nicolaou et al., J. Chem. Soc., Chem. Commun. 1992, 1117-1118, J. Chem. Soc., Chem. Commun. 1992, 1118-1120, and J. Chem. Soc., Chem. Commun. 1993, 1024-1026. Several synthetic taxol analogs have also been developed and have been found to have altered chemical and biological activity as compared to natural taxol, e.g., K. C. Nicolaou et al., Nature, 1993, 364, 464-466. There is considerable interest in the design and production of further taxol analogs. However, progress with respect to the synthesis of such taxol analogs has been blocked by a lack of information regarding certain key synthetic methods and key intermediates essential for the production of a wide range of taxol analogs.
What is needed is the identification of key synthetic methods and key intermediates for producing taxol analogs having altered activities.